diff --git a/lib/ast.ml b/lib/ast.ml
index 46fc1a4..3eeeed2 100644
--- a/lib/ast.ml
+++ b/lib/ast.ml
@@ -69,6 +69,8 @@ and expression_primary =
   | DateLiteral of string
   | TimeLiteral of string
   | TimestampLiteral of string
+  | IntegerLiteral of int
+  | FloatLiteral of float
   | Concatenation of expression_primary * expression_primary
   | Numeric of expression_primary * sign * expression_primary
   | Signed of sign * expression_primary
@@ -103,8 +105,18 @@ and pp_expression exp =
   | DateLiteral(d) -> "'" ^ d ^ "'"
   | TimeLiteral(t) -> "'" ^ t ^ "'"
   | TimestampLiteral(ts) -> "'" ^ ts ^ "'" 
+  | IntegerLiteral(i) -> string_of_int i
+  | FloatLiteral(f) -> string_of_float f
+  | Numeric(n1, s, n2) -> pp_expression n1 ^ pp_sign s ^ pp_expression n2
   | _ -> "Expression not yet supported"
 
+and pp_sign sign =
+  match sign with 
+  | Plus -> "+"
+  | Minus -> "-"
+  | Times -> "*"
+  | Divide -> "/"
+
 and pp_table_expression table_exp =
   match table_exp with
   | TableExpression(tables, filter, _) -> pp_tables tables ^ pp_filter filter